Add helper for icons on quickstart and cartridge tiles
Bail out on upgrade in a more shell-friendly way

Manipulating env var might be problematic
Pull logo haml generation into a helper
Bug 1018665

Reraise the ShellExecutionException in build() so it's seen as a
failure and halts the deployment
UI tweaks
Merge pull request #3921 from BanzaiMan/dev/hasari/bz1020177

Merged by openshift-bot
Merge pull request #3917 from jwforres/tile_logos

Merged by openshift-bot
Merge pull request #3926 from ncdc/bz1018665

Merged by openshift-bot
Merge pull request #3927 from liggitt/ui_tweaks

Merged by openshift-bot